Recently there have been many advances in community file sharing technology, and in technology required for digitally encoding music data, audio and/or visual data. These advances allow people (or machines) to easily share and exchange such data, either directly or indirectly though sharing services. Such sharing technology can be used to aid proliferation of commercial and non-commercial data, such as music. A significant issue hindering such proliferation, is difficulty in enforcing copyrights and/or sharing policies for certain data.
For example, one may desire to “rent” a song, or a movie, by allowing one to download the song or movie, such that it can only be played a certain number of times, or only for a given time period. To effect such restraints, costly and complex security techniques are typically employed to control digital data distribution. Such security techniques increase the costs of providing data to consumers, increase costs for devices to present the data, and provide more opportunity for problems to occur.